“We have about five more years at the outside to do something.” • Kenneth Watt, ekolog

"The world has been chilling sharply for about twenty years. If present trends continue, the world will be about four degrees colder for the global mean temperature in 1990, but eleven degrees colder in the year 2000. This is about twice what it would take to put us into an ice age."• Kenneth Watt

“Five years is all we have left if we are going to preserve any kind of quality in the world.” • Paul Ehrlich, populationsbiolog, Stanford Universitet

"In ten years all important animal life in the sea will be extinct. Large areas of coastline will have to be evacuated because of the stench of dead fish."• Paul Ehrlich

"Population will inevitably and completely outstrip whatever small increases in food supplies we make. The death rate will increase until at least 100-200 million people per year will be starving to death during the next ten years."• Paul Ehrlich

"By the year 2000, thirty years from now, the entire world, with the exception of Western Europe, North America, and Australia, will be in famine"• Peter Gunter, professor i miljöfilsofi vid North Texas State University

“Civilization will end within 15 or 30 years unless immediate action is taken against problems facing mankind.” • George Wald, biolog, Harvard Universitet

“We are in an environmental crisis which threatens the survival of this nation, and of the world as a suitable place of human habitation.” • Barry Commoner, biolog, Washington Universitet

“Man must stop pollution and conserve his resources, not merely to enhance existence but to save the race from intolerable deterioration and possible extinction.”• New York Times editorial, dagen efter Earth Day

Earth Day 1990:

"Measured on virtually any scale, the world is in worse shape than it was 20 years ago."• Dennis Hayes, ordförande för Earth Day 1990

Några andra uttalanden:

"Isn’t the only hope for the planet that the industrialized civilizations collapse? Isn’t it our responsibility to bring that about?"• Maurice Strong, grundare av FN:s Environment Programme (UNEP)

"The prospect of cheap fusion energy is the worst thing that could happen to the planet."• Jeremy Rifkin, Greenhouse Crisis Foundation

"Giving society cheap, abundant energy would be the equivalent of giving an idiot child a machine gun."• Paul Ehrlich

"Adopting a central organizing principle means embarking on an all-out effort to use every policy and program, every law and institution, every treaty and alliance, every tactic and strategy, every plan and course of action to use, in short, every means to halt the destruction of the environment."• Al Gore i boken Earth in the Balance

"Effective execution of Agenda 21 will require a profound reorientation of all human society, unlike anything the world has ever experienced a major shift in the priorities of both governments and individuals and an unprecedented redeployment of human and financial resources. This shift will demand that a concern for the environmental consequences of every human action be integrated into individual and collective decision-making at every level."• FN:s Agenda 21

"In Nature organic growth proceeds according to a Master Plan, a Blueprint. Such a ‘master plan’ is missing from the process of growth and development of the world system. Now is the time to draw up a master plan for sustainable growth and world development based on global allocation of all resources and a new global economic system. Ten or twenty years form today it will probably be too late."• Mihajlo Mesarovic och Eduard Pestel i Romklubbens andra rapport, Mankind at the Turning Point (1974)

"One America burdens the earth much more than twenty Bangladeshes. This is a terrible thing to say. In order to stabilize world population,we must eliminate 350,000 people per day. It is a horrible thing to say, but it's just as bad not to say it."• Jacques Cousteau, ur intervju i UNESCO Courier

"Climate is an angry beast and we are poking at it with sticks"• Wallace Broecker, Lamont-Doherty Earth Observatory, New York (2003)

"Unless we announce disasters no one will listen."• Sir John Houghton, IPCC:s första ordförande

"One of the self-identified "founders" of Earth Day, Bay Area activist John McConnell, has written that in 1969 he proposed to the San Francisco Board of Supervisors a new holiday to be called Earth Day on the first day of spring, the Equinox, around March 21. But, he writes, in 1970 local anti-Vietnam War and Environmental Teach-in activists "who were planning a one-time event for April 22, also decided to call their event Earth Day."

And what was this unnamed "one-time event" in 1970? It was the 100th birthday celebration for Vladimir Ilyich Ulyanov, known to history as Lenin [...]"

"Anyone who goes around and says that carbon dioxide is responsible for most of the warming of the 20th century hasn't look at the basic numbers."Patrick Michaels - Ph.D. Ecological Climatology, Professor of Environmental Sciences, U. of Virginia

“We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it.”Phil Jones, Professor in the School of Environmental Sciences at University of East Anglia, to Steve McIntyre